Wednesday, 22 March 2017

I recently gave a talk on Brettanomyces and sour beers at work, included in which was a brief overview of sour and Bretty beer styles. Explaining what gose was lead to me getting some horrified looks. Does sour and salty beer, often with added fruit, sound unappealing I wondered? So I had to get some for my colleagues to try. I went home via Dorking that night and called in at Cobbett's Real Ales to pick up a can of Magic Rock Salty Kiss, a beer I must confess I hadn't been taken with when I first tried it. As is usually the case with me the drinking though, this was purely for research purposes so whether I enjoyed it or not was irrelevant.

I split the can between six of us, and no sooner had a started pouring than people were asking "is it meant to be cloudy?". "Yes, it's craft beer" I replied. But was that a touch of snark creeping into my voice? I do find the thought of ahistorical historical beers slightly grating. And I've a sneaking suspicion that a beer called Salty Kiss is a prime candidate for public shaming on Pump Clip Parade. So I summoned up my best scientific objectivity and resolved to act in an unbiased and professional manner. I was somewhat lost for words when the next question was "is it meant to have floaters?". Haze can be perfectly acceptable in some styles of beer, wheat beers included*. Floaters though? Noticeable dark bits bobbing round in the beer? Surely that has to be considered a fault. So I just muttered again "yes, it's craft beer" and pressed on.

The reaction to the tasting wasn't great, and despite the small amount of beer I'd put in each glass three weren't finished.

But on the other hand, three were. One of my colleagues said he could see if being a refreshing beer on a hot day, though thought the salty after taste detracted from this slightly. As for myself, I actually noticed a lot less salt than last time, and emptied my glass quite easily. I really need to try it on a hot day next, maybe I'll get why people like it then.

*Though I'm not sure if is Salty Kiss is a wheat beer, it wasn't listed on the ingredients but was listed as an allergen.

Sunday, 19 March 2017

The trouble with brewing with the Orval Brettanomyces is that it's a complete beast. The first time I tried brewing with it it pulled on it's hobnail boots and trampled over all the other flavours I'd tried to get in the beer. It seems to me to brew successfully with it you need to limit its growth as much as possible or the beer will become unbalanced.

I reviewed the information I'd got when I visited the brewery and this is very much what they do there:

Mash at 60°C so there's maximum fermentability for the primary fermentation with Saccharomyces.

Include a large proportion of 100% fermentable sugar for the primary fermentation.

When bottling the beer pitch 99% Saccharomyces and 1% Brettanomcyes for the secondary fermentation.

Apparent attenuation is over 90% before the Brett. is added, though it does get to 100% after the secondary fermentation.

Armed with this knowledge my latest attempt at making an Orval like beer had a long and low temperature mash, with a very small Brett. addition on bottling...and it worked! I got acrisp tasting beer with a touch of funk and no nitrogenation. I'm rather pleased with this one.

Monday, 6 March 2017

As promised the excellent Joe Hertrich has returned to the Master Brewers' Association of the Americas podcast to talk some more about malt. This time it's about the bits missing from his last talks: flavour and aroma.

Unlike colour flavour and aroma cannot be defined by a number but are defined by kilning technique. Though steeping and germination are fairly uniform throughout the industry there is a lot of variation in kilning. It is the most energy intensive process in malting due to the electric fans and fossil fuel heat.

Unless you have a dialogue with your maltster they will focus on meeting the specs on moisture, colour and not destroying DP (Diastatic Power).

Colour, flavour and enzymes are liked. Flavour compound development is parallel to colour development and enzyme destruction. For example, distillers malt has very low colour and very high enzyme content. Pale malt has more flavour but less enzymes. Very little flavour or colour is created below 60°C (the temperature distillers malts are kilned at). If the same green malt split and kilned to make distillers malt and pale malt the distillers malt will have 220 DP and the pale malt 140.

Enzyme conversion creating Maillard reaction precursors happens around mash temperatures (63-68°). Simple enzymes will have been created already in well modified malts and simple sugars will be created in the kiln at these temperatures. Amines and sugars are the Maillard precursors. This conversion phase can be controlled to emphasise it or de-emphasise it.

Green and grassy flavours are eliminated in the kiln at around 80-85°C. Lipoxygenase is also eliminated at 85°C (so why use null lox barley?).

At high temperatures and low moistures Maillard reactions create melanoidins. Light melanoidins are biscuity and toasty, dark melanoidins are more like coffee and black chocolate, with toffee flavours in the middle. Caramelisation does not happen in the kiln, only in the roaster.

Withering is the free drying of surface moisture of green malt. It is carried out with high air flow and low temperature and the moisture content goes from around 45% to 12%. High humidity air will come off the kiln. At the break point when the free moisture has been drive off curing starts and the bound moisture is removed with high temperature air which will leave the kiln at low moisture content. The moisture content will from from 12% to around 4%. Each of these phases uses half the kilning energy.

Lager malt is designed for adjunct brewers. It as minimal flavour and is made with very rapid air flow but minimal temperature so minimal Maillard reaction precursors are formed and minimal melanoidins created. It is cured at 80-85°C just on the borderline of driving out the green and grassy flavours. It will have low colour, high DP (140) and lipoxygenase will still be active.

It's not the best base malt for all malt craft brewers, who should look to other malts.

English pale ale malt is the strongest base malt, better than US pale or German pilsner. Kilned with rapid air flow and low temperature until the break point and then cured at a higher temperature than US pale, 90-105°C at the end when moisture very low. This give twice the colour of US pale at 7.1 EBC. It's not unusual to have UK pale malt at less than 3% moisture. DP is 90 or 100 with no lipoxygenase. The real value is in the flavour notes though: no raw grain flavours whatsoever.

Light melanoidins formed by the little Maillard reactions there were, giving a toasty biscuity flavour. Much cleaner and with all the green grassy and weak aroma eliminated. German pilsner malt lets you produce a German flavour: grainy and high in DMS. In the US for English type pale malts you want "high dried".

If you want flavour there's also Vienna malt. In the withering process there is also a little re-circulation as temperature increases so more heat goes to a high moisture grain and some enzyme conversion occurs and a higher amount of Maillard reactions occur. Kilning is at 90-96°C. Raw grain flavours are eliminated by now you get more of the darker, sweeter, melanoidins which a lot of people think of as malty flavour

The light Munich types start with significant recirculation and hold when still above 25% moisture to get ezymic conversion before the moisture is gone and significant Maillard reactions occur. When heated to 100-105°C you get malty and sweet aromatics due to Maillard reaction products. If you're after flavour you will have to accept higher colour and lower DP, but Munich malt will still have enough enzymes for starch conversion.

"Lower colour expectations are the enemy of malt flavour". Maltsters looking for low colour will first have to seek low protein barley and make less modified malt so the amount of simple amines is reduced. But this reduces overall malt functionality and extract. Then there be low temperature, high flow klinings with minimum cure temperature to avoid melanoidin formation, but this risks green grassy notes. It makes no sense to use very pale malts with darker speciality malts.

Roasting is carried out in very small batches compared to white malts, also for a short time (2.5-3) hours. Malt is put in a drum and heat applied. This can be done without drying, which you can't do in a kiln. You can apply heat to low moisture grain but most roasters are loaded with green malt directly from germination at around 45% moisture. You can put it up to mashing temperature and do mini-mashing in the roaster. Temperatures can go up to 175-260°C, depending on the depth of the flavour and colour required. Caramelisation of sugars will occur, and all enzymes are destroyed.

If barley variety makes a difference to malt flavour it is very small. Differences in malting processes make much greater difference, both between different malting plants and the different processing and kilning that different barley varieties may need to make malt of the same specification. So though flavour differences do exist they are due to the malting and not barley genetics.